Check for IPython version.

IHaskell/Eval/Evaluate.hs

@@ -23,6 +23,7 @@ import GHC hiding (Stmt)
 import GHC.Paths
 import Exception hiding (evaluate)
 
+import Outputable
 import qualified System.IO.Strict as StrictIO
 
 import IHaskell.Types
@@ -164,7 +165,9 @@ evalCommand (Statement stmt) = do
   ghandle handler $ do
     (printed, result) <- capturedStatement stmt
     case result of
-      RunOk _ ->
+      RunOk names -> do
+        dflags <- getSessionDynFlags
+        write $ "Names: " ++ show (map (showPpr dflags) names)  
         return [Display PlainText printed]
       RunException exception -> do
         write $ "RunException: " ++ show exception

IHaskell/IPython.hs

 module IHaskell.IPython (
   runIHaskell,
-  setupIPythonProfile
+  setupIPythonProfile,
+  ipythonVersion
 ) where
 
 import ClassyPrelude
@@ -9,6 +10,10 @@ import Text.Printf
 import System.Argv0
 import System.Directory
 import qualified Filesystem.Path.CurrentOS as FS
+import Data.List.Utils (split)
+
+import Prelude (read)
+import qualified System.IO.Strict as StrictIO
 
 import qualified IHaskell.Config as Config
 
@@ -23,6 +28,17 @@ ipython args = do
             doNothing _ _ _ = return ()
 
 
+-- | Use the `ipython --version` command to figure out the version.
+-- Return a tuple with (major, minor, patch).
+ipythonVersion :: IO (Int, Int, Int)
+ipythonVersion = shelly $ do
+  path <- which "ipython"
+  case path of
+    Nothing -> error "Could not find `ipython` executable."
+    Just path -> do
+      [major, minor, patch] <- map read <$> split "." <$> runHandle path ["--version"] (liftIO . StrictIO.hGetContents) :: Sh [Int]
+      return (major, minor, patch)
+
 -- | Run an IHaskell application using the given profile.
 runIHaskell :: String   -- ^ IHaskell profile name. 
            -> String    -- ^ IPython app name.

Main.hs

@@ -3,6 +3,7 @@
 import ClassyPrelude hiding (liftIO)
 import Control.Concurrent.Chan
 import Data.Aeson
+import Text.Printf
 
 import qualified Data.Map as Map
 
@@ -20,6 +21,11 @@ data KernelState = KernelState
 
 main ::  IO ()
 main = do
+  (major, minor, patch) <- ipythonVersion
+  when (major /= 1) $ do
+    printf "Expecting IPython version 1.*, found version %d.%d.%d.\n" major minor patch
+    error "Incorrect ipython --version."
+
   args <- map unpack <$> getArgs
   case args of
     -- Create the "haskell" profile.